#define BUTTON 12
#define LED 13

void setup() {
  // put your setup code here, to run once:
  pinMode(BUTTON, INPUT_PULLUP);
  pinMode(LED, 13);
}

void loop() {
  // put your main code here, to run repeatedly:
  if (digitalRead(BUTTON) == LOW){
    delay(20);
    if (digitalRead(BUTTON) == LOW){
      digitalWrite(LED, !digitalRead(LED));
    }
    while (digitalRead(BUTTON) == LOW);
  }
}
